In this paper, we would like to address the problem of using unreliable, yet valuable services in SOA design. We first give a new classification of services based on their service QoS levels and their deployment modes. Then, instead of driving for higher QoS level from a single service, we achieve the same goal through the concept of "Service Community". Both the system design issues and the corresponding architecture are given. The importance of this new architecture is that valuable but unreliable services on internet can now be used as components in SOA just like those high QoS ones, but with a substantially lower cost.